Parathyroid & Endocrine Glands Cancer

Parathyroid carcinoma is the rarest endocrine malignancy, arising from the chief cells of one of the four parathyroid glands located adjacent to the thyroid in the neck. The parathyroid glands regulate calcium metabolism by secreting parathyroid hormone (PTH). In parathyroid carcinoma, unregulated PTH secretion causes severe, symptomatic hypercalcaemia — often the feature that prompts clinical investigation. The diagnosis is suspected when serum calcium is markedly elevated (often >3.5 mmol/L) alongside very high PTH levels in a patient with symptoms of hypercalcaemia — bone pain, kidney stones, nausea, confusion, and fatigue. Imaging (CT neck, sestamibi scan) localises the tumour. The definitive diagnosis of malignancy is made at pathology by identifying features of invasion (vascular, capsular) or confirmed by the subsequent development of local recurrence or distant metastases.

Phaeochromocytoma secretes catecholamines — adrenaline and noradrenaline — causing the classic triad of paroxysmal severe headache, profuse sweating, and palpitations, usually accompanied by a sudden rise in blood pressure. Attacks may last minutes to hours and can be triggered by physical exertion, postural changes, abdominal pressure, or certain medications. Between attacks, blood pressure may be persistently elevated and resistant to standard antihypertensive treatment. Not all phaeochromocytomas are symptomatic — a small proportion are biochemically silent or discovered incidentally on imaging. The diagnosis is confirmed by elevated plasma free metanephrines or 24-hour urine fractionated catecholamines, followed by imaging to localise the adrenal tumour.

Surgical manipulation of a phaeochromocytoma — cutting, compressing, or mobilising the adrenal tumour — causes massive catecholamine release into the circulation, which can trigger a life-threatening hypertensive crisis with systolic blood pressure exceeding 250–300 mmHg, resulting in stroke, myocardial infarction, arrhythmia, or death. Pre-operative alpha-adrenergic blockade — typically with phenoxybenzamine or doxazosin for at least 10–14 days before surgery — blocks the catecholamine receptors in blood vessel walls, preventing this dangerous pressure surge during tumour manipulation. Beta-blockade is added only after adequate alpha-blockade is established, as beta-blockade alone in the presence of alpha-mediated vasoconstriction can precipitate a paradoxical severe hypertensive crisis.

More than 30% of phaeochromocytomas and paragangliomas harbour a germline (inherited) driver mutation — a rate far higher than most cancers. The most important hereditary genes are: SDH genes (SDHB, SDHC, SDHD, SDHAF2 — collectively the most common hereditary PPGL drivers); VHL (Von Hippel-Lindau syndrome — bilateral phaeochromocytomas with renal cell carcinoma and haemangioblastomas); RET (MEN2A and MEN2B — with medullary thyroid carcinoma); and NF1 (neurofibromatosis type 1). SDHB mutations carry the highest risk of malignant transformation (~40%). Because the hereditary fraction is so high, all patients with phaeochromocytoma or paraganglioma should receive germline genetic testing at diagnosis, regardless of family history or age at presentation.

Thymoma and thymic carcinoma are both malignant tumours of the thymus — a gland in the anterior mediastinum (between the sternum and the great vessels) that is the site of T-lymphocyte maturation. Thymoma is the more common and less aggressive type — it retains some resemblance to normal thymic tissue and is classified into subtypes (WHO A, AB, B1, B2, B3) based on its histologic appearance. Thymoma is uniquely associated with autoimmune paraneoplastic conditions — most commonly myasthenia gravis, in which antibodies attack the acetylcholine receptor at the neuromuscular junction, causing fatigable muscle weakness. Thymic carcinoma is a higher-grade, more aggressive tumour with no resemblance to normal thymus and no association with myasthenia gravis. It more often presents at advanced stage and requires systemic treatment including chemotherapy, targeted therapy, and immunotherapy.

Pembrolizumab is generally avoided in thymoma (Types A through B3) and is used with extreme caution when considered. The reason is that thymoma is associated with a dysregulated immune system — and pembrolizumab (anti-PD-1 checkpoint inhibitor), by releasing immune checkpoints, dramatically increases the risk of severe autoimmune toxicities in thymoma patients. Cases of fatal myocarditis, severe myositis, myasthenia gravis exacerbation, and multi-organ immune attack have been reported in thymoma patients receiving pembrolizumab. In thymic carcinoma — where the tumour has no immune system association — pembrolizumab is used at second line for PD-L1-positive disease with intensive immune monitoring, and has demonstrated meaningful response rates.

Pineal tumours arise from the pineal gland — a small gland at the centre of the brain that produces melatonin. Because the pineal gland is located adjacent to the cerebral aqueduct (the pathway through which cerebrospinal fluid circulates), even small pineal tumours frequently obstruct CSF flow, causing obstructive hydrocephalus — a buildup of fluid in the brain. The characteristic symptoms are severe morning headache, nausea, and vomiting from raised intracranial pressure; Parinaud's syndrome (inability to look upward, from compression of the dorsal midbrain); and papilloedema. Pineal tumours range from pineocytoma (slow-growing, Grade 1, often cured by surgery) to pineoblastoma (highly malignant, Grade 4, treated intensively with surgery, craniospinal radiation, and high-dose chemotherapy).

Lu-DOTATATE (Lutathera) is peptide receptor radionuclide therapy (PRRT) — a systemic treatment in which a radiolabelled somatostatin analogue (DOTATATE) delivers targeted radiation to tumour cells that express somatostatin receptors on their surface. Malignant phaeochromocytomas and paragangliomas — particularly SDH-mutant tumours — express somatostatin receptors at very high density, making them excellent candidates for this approach. Eligibility is confirmed by 68Ga-DOTATATE PET-CT, which demonstrates high tracer uptake in the tumour lesions. Patients with DOTATATE-avid, inoperable, or metastatic malignant PPGL are candidates for Lu-DOTATATE at specialist PRRT centres. It provides disease control, reduction in catecholamine burden, and symptom improvement in a significant proportion of patients.

Each endocrine tumour covered here has a significant hereditary component. The key syndromes to consider are: Hyperparathyroidism-Jaw Tumour (HPT-JT) syndrome (CDC73/HRPT2 mutations) for parathyroid carcinoma; Hereditary PPGL syndromes including SDH-related PPGL syndrome (SDHB/C/D/AF2), VHL syndrome, MEN2A and MEN2B (RET), and neurofibromatosis type 1 (NF1) for phaeochromocytoma/paraganglioma; MEN1 syndrome (MEN1 gene) for thymic carcinoid; and Trilateral Retinoblastoma (RB1 germline mutation) for pineoblastoma in children. Germline testing for the relevant gene panel at diagnosis is now clinical standard for all four tumour types.

Yes. CancerFax supports patients with parathyroid carcinoma, thymoma, thymic carcinoma, malignant phaeochromocytoma/paraganglioma, and pineal tumours in accessing specialist endocrine oncology and endocrine surgery second opinions, germline genetic testing coordination and hereditary syndrome evaluation, PRRT (Lu-DOTATATE) eligibility assessment and specialist PRRT centre access for malignant PPGL, pembrolizumab eligibility review for thymic carcinoma, specialist paediatric neuro-oncology access for pineoblastoma, and clinical trial identification based on tumour type and molecular profile at centres in China and globally. Share your medical reports and biochemical results with our team to begin.